Method for working and heat-treating a copper base alloy



Patented June 3, 1,952

METHOD FOR WQRKING VAND HEAT-TREAT@ ING `A COPPER BASE ALLOY John "'Klemen-t, Milwaukee, Wis., .assi'gnor to Ampco ,Metal lnc., Milwaukee, Wis., a corporation of Wisconsin .No Drawing'. Application September 20, 1948, Serial No. 50,243

-L11-Claims. 1 A.lliis' invention relates to a .copper base alloy which :may housed/as an Voverlay material and alsoaas a Joining material.

' v'Loe :principalobject of the invention is to lprovide .such an .alloy which is particularly adaptable 'for use as a` metal spray `and as a weld metal which fis applied automatically.

Another object vof the invention :is to provide such .an alloy which possesses excellent lbearing and Wear resistant qualities, .and :at the same time, is suiiiciently tductifle so that it may be easily handled in a metal spray .gun .and also in automatic welding machines.

Another. object Aof the invention is to provide .a metallurgical treatment lfor such an alloy whereby the alloy is .made sufficiently ductile and is setin this .condition thereby making the same commercially desirable for its intended use.

'Other :objects and advantages of the invention will appear hereinafter.

Inthe art of metal spraying andxautolnatic weldine', .only .certain alloys have 'been generally suitable; tor instance, regular bras's ,of a ycom- `position 851% copper and 15% zinc, regular mild ment.

According tothe invention, the aluminum bronze alloy is composed of copper, aluminum, iron and other ingredients in substantially the following ranges of compositions for the corresponding ingredients:

Per cent Ammamm k 7.o to 10.5 man.,` e 0.o to 3.5 others 0.5 Coppens l l v Balance Apreferred composition is as follows:

1.2.5 maximum It will be understood that-various other ingre- 'clients such `as silicon, nickel, manganesewetc.

.may be included .in the composition of the alu minum bronze alloy -of the invention, and that the hereinafter described heat treatment may `b,e used .successfully in connection `with these :alloy compositions.

In order to produce an aluminum bronze alloy of the above composition that would .serve .successfully for metal spraying or .automatic welding it has been found necessary to subject the alloy to a high temperature soak following by furnace cooling to a predetermined temperature. The alloy is next given a Water quench and then a :low temperature soak.

Asa specific example, if a 0.125" aluminum bronze spray or automatic weld `Wire is desired, .a preferred practice is to start with 0.225 stock.

lpreferably extended, .and ,drawl it down to alp-- `proximately 0.128". The .stock could, of course, -be hot swaged, but the cost of this vmetl'iodof re `duction is substantially prohibitive and thetolerance limits required make this method unsuitable `for the purpose. The partially Worked 'wire is coiled as it comes from the extension press and the coils are placed in a furnace ata temperature of approximately l`600 F. Afterf soaking for about 15 to 30 minutes at this temperature, the temperature of the furnace is reduced about 200 to 300 F. per hour until it reaches approximately 1100" F. At this temperature, which is above `the eutectoid transformation point, the 'maximum amount of alpha'will precipitate.

After the above treatment, the H.coils .of lalum'inum bronze alloy Wire are given .a quench to yprevent the formation of any detrimental eutectoid phase. The quench may be by submergtng the coils in plain Water or salt water.

The wire is then given a final draw which reduces its vdiameter to the diameterv .desired in the -nal product. In 'the example given, the draw would be 0.003" and the ilnal diameter di the wire, 0.125".

The wire is next given a low temperature heat treatment at a temperature below that of the eutectoid transformation. This temperature may be from 400 to 600 F. but the preferred temperature is approximately 500 F. This will set 'the wire so that it will not be wild when released virmu the coils for easy manipulation in a spray gunoi' automatic welding apparatus.

It is preferable that the wire `then 'be :oleane .So that the deposited lmetal,'whether it .be from .a spray gun 'or Vfrom automatic Welding apparatus, will be free from oxides that are .of .a detrimerrtel nature."

The high temperature treatment of the coils of aluminum bronze alloy wire, followed by slow cooling to a temperature above the temperature for eutectoid transformation, puts the wire in a condition so that the final draw can be accomplished in one pass vthrough the drawing die. The Wire is not subject to breakage as would be generally the case if the above steps of treating rwere not followed. During the nal drawing operation it has been found that exceedingly close tolerances of diameter may be obtained.

The physical properties of an aluminum bronze sprayed deposit of the preferred alloy composition treated as above described are:

85-90 Rockwell B 90,000100,000 p. s. i. compressive strength 25,000-35,000 p. s. i. ultimate tensile strength 0.5% elongation in 2" 80,60091,700 p. s. i. ultimate tensile strength .46,000-41000 p. s. i. yield 0.5 elongation 13.5-25.0% elongation in 2" 6.5-16.0% reduction of area 235-245 Brinell-hardness on steel overlay.

'I'he method of this invention may be used with any aluminum bronze alloy composition in which there is a substantial alpha plus beta range existing between the temperature for beta formation and the temperature for eutectoid formation. The controlled slow cooling from the high soaking temperature of substantially 1600 F. to a temperature above the temperature of eutectoid i transformation permits the maximum amount of alpha to precipitate; The microstructure of an aluminum bronze alloy of the above type, when treated according to the invention, will be very uniform both in longitudinal and transverse section and will show a large uniform grain size. The alpha size is generally about .045 milimeter.

The/invention is generally applicable to the above type aluminum bronze alloy which has been worked such as being drawn, extruded, rolled or forged as distinguished from such an alloy in the as cast condition.

Various embodiments of the invention may be employed within the scope of the accompanying claims.

I claim: Y

`1. The method of heat treating a worked aluminum bronze alloy having a substantial alpha plus beta temperature range disposed between a beta temperature range and a range of temperatures for eutectoid transformation, which comprises heating said alloy to within the beta temperature range, gradually reducing said temperature to above the range of temperatures for eutectoid transformation to obtain alpha precipitation quenching said alloy, and thereafter heating said alloy to a predetermined tempera- -ture below the range of temperatures for eutectoid transformation.

2. The method of heat treating a worked aluminum bronze alloy having a substantial alpha plus beta temperature range disposed between. a ..beta temperature range and a range `of temperatures for eutectoid transformation,

Cil

which comprises heating said alloy to within the beta temperature range, gradually reducing said temperature to above the range of temperatures for eutectoid transformation to obtain alpha precipitation, and thereafter quenching said alloy.

formation, quenching said alloy, and thereafter heating said .alloyy to a temperature of approximately 500 F.

4. The method of heat treating an aluminum u bronze alloy for use as a welding or overlay material having an aluminum content of from '7.0 to 10.5% and of high wear resistant characteristics to impart ductility thereto, which comprises heating said alloy to approximately 1600 F., gradually reducing said temperature to a predetermined temperature above the range of temperatures for eutectoid transformation, quenching said alloy and thereafter heating said alloy to a predetermined temperature below the range of temperatures for eutectoid transformation.

5. The method of Vheat treating a worked aluminum bronze alloy having an aluminum content of from '7.0 to 10.5% and of high wear resistant characteristics to impart ductility thereto, which comprises subjecting said alloy to a high temperature soak of lapproximately 1600 F., gradually reducing said temperature to a predetermined temperature above the range-of temperatures for eutectoid transformation to permit a maximum amount of alpha to precipitate, and thereafter quenching said alloy to prevent formation of the eutectoid phase.

6. The method of heat treating an aluminum bronze alloy for use as a welding or overlay material having an aluminum content of from 7.0 to 10.5% and of high wear resistant characteristics to impart ductility thereto, which comprises subjecting said alloy to a high temperature soak of approximately 1600 F., gradually reducing said temperature to a predetermined temperature above the range of temperatures for eutectoid transformation to permit a maximum amount of alpha to precipitate, quenching said alloy to prevent formation of the eutectoid phase, and thereafter heating said alloy to a predetermined temperature below the range of temperatures for eutectoid transformation to impart a set to said alloy.

7. The method if heat treating an aluminum bronze alloy having an aluminum content of from '7.0 to 10.5 and of high wear resistant characteristics, which comprises applying to lsaid alloy a high temperature furnace soak at approximately 1600 F., gradually vreducing said temperature to a predetermined temperature of approximately 1100 F. to impart ductility to said alloy, quenching said alloy, and thereafter heating said alloy to a predetermined temperature below the range of temperature for eutectoid transformation to increase the yield strength thereof and to impart a set to said alloy and to retain said ductility.

8. The method of heat treating an aluminum bronze alloy wire having an aluminum content of. from about '7% to about 10.5% and of high Wear resistant characteristics and adapted for use in metal spray and automatic welding equipment,

` which comprises heating said wire to a temperature of approximately 1600 F., reducingl said 5 temperature at a rate of about 200-300 F. per hour to about 1100 F. to impart ductility to said wire, quenching said wire, and thereafter heating said wire to approximately 500 F. to impart a set to said wire and thereby retain ductility in said wire.

9. In the manufacture of an aluminum bronze alloy Wire having an aluminum content of about from 7% to about 10.5% and of high wear resistant characteristics and adapted for use as a metal spray and in automatic welding equipment, the steps which comprise imparting a plurality of alternate breakdown draws and anneals to wire stock, forming said stock into coils of suitable length, heating said coils to a temperature of approximately 1600 F., gradually reducing the temperature of said coiled wire to above the range of temperatures for eutectoid transformation, quenching said coils, imparting a iinal drawing to said wire, forming said wire into coils, and thereafter heating said coils to a temperature below the range of temperatures for eutectoid transformation to impart a Set to said coiled wire.

10. The method of heat treating a high strength aluminum bronze alloy wire of the following constituents in substantially the percentage ranges given:

Per cent Aluminum 7.0 to 10.5 Iron 0.0 to 3.5 Others 0.0 to 0.5 Copper balance to impart ductility thereto preparatory to drawing the same to diameters of approximately 1/8 inch or less with diameter tolerances of .0005 inch plus or minus, which comprises heating said wire to a temperature of approximately 1600 F., reducing said temperature at a rate of about 200- 300 F. per hour to approximately 1100 F. which is just above the eutectoid transformation point, and then quenching said wire from said 1100 F.

11. The method of producing a drawn high strength bronze alloy wire having a diameter tolerance less than about .0005 inch plus or minus and for use in metal spray and automatic welding equipment, comprising rst producing a roughly drawn wire of excess diameter and of the following constituents in substantially the percentage ranges given:

Per cent Aluminum 7.0 to 10.5 Iron 0.0 to 3.5 Others 0.0 to 0.5 Copper balance REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,502,857 Leitner July 29, 1924 2,057,750 Munsen Jan. 14, 1936 2,033,710 Hensel Mar. 10, 1936 2,268,940 Hensel Jan. 6, 1942 OTHER REFERENCES Metals, vol. II, pages 1321 to 1326. Edited by Carpenter and Robertson. Published in 1939 by the Oxford University Press, London, England.

Metals Handbook, 1948 edition, page 1160. Published in 1948 by The American Society for Metals, Cleveland, Ohio. 

5. THE METHOD OF HEAT TREATING A WORKED ALUMINUM BRONZE ALLOY HAVING AN ALUMINUM CONTENT OF FROM 7.0 TO 10.5% AND OF HIGH WEAR RESISTANT CHARACTERISTICS TO IMPART DUCTILITY THERETO, WHICH COMPRISES SUBJECTING SAID ALLOY TO A HIGH TEMPERATURE SOAK OF APPROXIMATELY 1600* F., GRADUALLY REDUCING SAID TEMPERATURE TO A PREDETERMINED TEMPERATURE ABOVE THE RANGE OF TEMPERATURES FOR EUTECTOID TRANSFORMATION TO PERMIT A MAXIMUM AMOUNT OF ALPHA TO PRECIPITATE, AND THEREAFTER QUENCHING SAID ALLOY TO PREVENT FORMATION OF THE EUTECTOID PHASE. 